Neuroprotection with the cannabigerol quinone derivative VCE-003.2 and its analogs CBGA-Q and CBGA-Q-Salt in Parkinson's disease using 6-hydroxydopamine-lesioned mice

Mol Cell Neurosci. 2021 Jan:110:103583. doi: 10.1016/j.mcn.2020.103583. Epub 2020 Dec 16.

Abstract

The quinone derivative of the non-psychotropic cannabinoid cannabigerol (CBG), so-called VCE-003.2, has been recently investigated for its neuroprotective properties in inflammatory models of Parkinson's disease (PD) in mice. Such potential derives from its activity at the peroxisome proliferator-activated receptor-γ (PPAR-γ). In the present study, we investigated the neuroprotective properties of VCE-003.2 against the parkinsonian neurotoxin 6-hydroxydopamine (6-OHDA), in comparison with two new CBG-related derivatives, the cannabigerolic acid quinone (CBGA-Q) and its sodium salt CBGA-Q-Salt, which, similarly to VCE-003.2, were found to be active at the PPAR-γ receptor, but not at the cannabinoid CB1 and CB2 receptors. First, we investigated their cytoprotective properties in vitro by analyzing cell survival in cultured SH-SY5Y cells exposed to 6-OHDA. We found an important cytoprotective effect of VCE-003.2 at a concentration of 20 μM, which was not reversed by the blockade of PPAR-γ receptors with GW9662, supporting its activity at an alternative site (non-sensitive to classic antagonists) in this receptor. We also found CBGA-Q and CBGA-Q-Salt being cytoprotective in this cell assay, but their effects were completely eliminated by GW9662, thus indicating that they are active at the canonical site in the PPAR-γ receptor. Then, we moved to in vivo testing using mice unilaterally lesioned with 6-OHDA. Our data confirmed that VCE-003.2 administered orally (20 mg/kg) preserved tyrosine hydroxylase (TH)-positive nigral neurons against 6-OHDA-induced damage, whereas it completely attenuated the astroglial (GFAP) and microglial (CD68) reactivity found in the substantia nigra of lesioned mice. Such neuroprotective effects caused an important recovery in the motor deficiencies displayed by 6-OHDA-lesioned mice in the pole test and the cylinder rearing test. We also investigated CBGA-Q, given orally (20 mg/kg) or intraperitoneally (10 mg/kg, i.p.), having similar benefits compared to VCE-003.2 against the loss of TH-positive nigral neurons, glial reactivity and motor defects caused by 6-OHDA. Lastly, the sodium salt of CBGA-Q, given orally (40 mg/kg) to 6-OHDA-lesioned mice, also showed benefits at behavioral and histopathological levels, but to a lower extent compared to the other two compounds. In contrast, when given i.p., CBGA-Q-Salt (10 mg/kg) was poorly active. We also analyzed the concentrations of dopamine and its metabolite DOPAC in the striatum of 6-OHDA-lesioned mice after the treatment with the different compounds, but recovery in the contents of both dopamine and DOPAC was only found after the treatment with VCE-003.2. In summary, our data confirmed the neuroprotective potential of VCE-003.2 in 6-OHDA-lesioned mice, which adds to its previous activity found in an inflammatory model of PD (LPS-lesioned mice). Additional phytocannabinoid derivatives, CBGA-Q and CBGA-Q-Salt, also afforded neuroprotection in 6-OHDA-lesioned mice, but their effects were lower compared to VCE-003.2, in particular in the case of CBGA-Q-Salt. In vitro studies confirmed the relevance of PPAR-γ receptors for these effects.

Keywords: 6-Hydroxydopamine; CBGA-Q; CBGA-Q-Salt; Cannabinoids; Mitochondrial dysfunction; PPAR-γ receptors; Parkinson's disease; VCE-003.2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antiparkinson Agents / chemical synthesis
  • Antiparkinson Agents / pharmacology
  • Antiparkinson Agents / therapeutic use*
  • Cannabinoids / chemistry*
  • Cell Line, Tumor
  • Humans
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Neurons / drug effects
  • Neurons / metabolism
  • Neuroprotective Agents / chemical synthesis
  • Neuroprotective Agents / pharmacology
  • Neuroprotective Agents / therapeutic use*
  • Oxidopamine / toxicity
  • PPAR gamma / antagonists & inhibitors
  • PPAR gamma / metabolism
  • Parkinson Disease / drug therapy*
  • Parkinson Disease / etiology
  • Quinones / chemistry*
  • Substantia Nigra / cytology
  • Substantia Nigra / drug effects
  • Substantia Nigra / metabolism

Substances

  • Antiparkinson Agents
  • Cannabinoids
  • Neuroprotective Agents
  • PPAR gamma
  • Quinones
  • VCE-003
  • Oxidopamine